title: Isomorphic red blood cells using automated urine flow cytometry is a reliable method in diagnosis of bladder cancer.
abstract: BACKGROUND
  We aimed to identify patients with a chief complaint of hematuria who could safely avoid unnecessary radiation and instrumentation in the diagnosis of bladder cancer (BC), using automated urine flow cytometry to detect isomorphic red blood cells (RBCs) in urine.
  
  
  METHODS
  We acquired urine samples from 134 patients over the age of 35 years with a chief complaint of hematuria and a positive urine occult blood test or microhematuria. The data were analyzed using the UF-1000i (®) (Sysmex Co., Ltd., Kobe, Japan) automated urine flow cytometer to determine RBC morphology, which was classified as isomorphic or dysmorphic. The patients were divided into two groups (BC versus non-BC) for statistical analysis. Multivariate logistic regression analysis was used to determine the predictive value of flow cytometry versus urine cytology, the bladder tumor antigen test, occult blood in urine test, and microhematuria test.
  
  
  RESULTS
  BC was confirmed in 26 of 134 patients (19.4 %). The area under the curve for RBC count using the automated urine flow cytometer was 0.94, representing the highest reference value obtained in this study. Isomorphic RBCs were detected in all patients in the BC group. On multivariate logistic regression analysis, only isomorphic RBC morphology was significantly predictive for BC (p < 0.001). Analytical parameters such as sensitivity, specificity, positive predictive value, and negative predictive value of isomorphic RBCs in urine were 100.0, 91.7, 74.3, and 100.0 %, respectively.
  
  
  CONCLUSIONS
  Detection of urinary isomorphic RBCs using automated urine flow cytometry is a reliable method in the diagnosis of BC with hematuria.
authors.affiliation: Department of Urology, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Muto
authors.forename: Syo-Ichiro
authors.initials: S
authors.lastname: Sugiura
authors.forename: Akiko
authors.initials: A
authors.lastname: Nakajima
authors.forename: Akira
authors.initials: A
authors.lastname: Horiuchi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Inoue
authors.forename: Keisuke
authors.initials: K
authors.lastname: Saito
authors.forename: Shuji
authors.initials: S
authors.lastname: Isotani
authors.forename: Raizo
authors.initials: R
authors.lastname: Yamaguchi
authors.forename: Hisamitsu
authors.initials: H
authors.lastname: Ide
authors.forename: Shigeo
authors.initials: S
authors.lastname: Horie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055088:Early Detection of Cancer; D004912:Erythrocytes; D005260:Female; D005434:Flow Cytometry; D006417:Hematuria / Q000473:pathology / Q000652:urine*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D001749:Urinary Bladder Neoplasms / Q000097:blood / Q000473:pathology / Q000652:urine*